Coach Ron Rivera hinted earlier this month that Stewart was on target to play in the opener, but the oft-injured runner -- who played in just nine games last season -- has been limited to riding a stationary bike this summer. Stewart has been wholly unreliable since signing a six-year, $37.811 million contract last August.

Stewart is scheduled to earn a $9 million option bonus in 2014, so it's possible this could be his final ride with the Panthers.

Until Stewart returns, Carolina's ground game -- which finished ninth in the NFL last season -- will center around DeAngelo Williams, rookie Kenjon Barner and the elusive Cam Newton. It's a major loss for the Panthers, who have enough talent to challenge for the NFC South but not enough depth on offense to be taken seriously.